There are several methods for ensuring that soil loses the least amount of water feasible. Plastic sheeting to cover the soil, mulching, and loosening the soil are some of these options.
Evaporation pans can be used to figure out when to irrigate certain crops. This strategy, however, only applies to large areas planted to crops in the same stage of development; thus, water loss by evaporation is uniform. Vegetables are exempt.
Evaporation from the soil surface and transpiration from the plant’s leaves both contribute to the loss of moisture.
The function of capillaries
Many factors influence the amount of water lost through soil evaporation. Compacted soil will lose more water than looser soil with a crumb structure, for example. This is due to capillary action, which allows moisture to crawl up surfaces despite gravity (the wick effect).
The wick effect, which causes moisture to rise, is broken by a crumb structure. By disrupting the upward passage of moisture by loosening the soil’s surface layer, you’re also interfering with the wicking activity.
Tramping on loose, moist dirt and returning to the place a few days later will reveal this effect. Your shoe print will still be wet, while the surrounding surface will be dry.
This is because the earth beneath the shoe has been squeezed, increasing the capillary action of fluids beneath the surface. This water has moved upwards in a short amount of time to reach the footprint’s surface. Water loss is influenced by soil condition.
a layer of soil
Using a covering on the soil can also help to prevent moisture loss. Plastic covers are commonly used for this purpose, and if black, they will prevent sunlight from reaching the soil surface, allowing weeds to sprout. Black sheeting also absorbs heat from the sun’s rays, which can assist warm the soil for faster plant growth in chilly situations.
It can, however, cause the soil to get overly heated in hot weather. As a result, black plastic is commonly utilized on the underside, whereas white plastic is used on the face of the sun.
These coverings not only keep the soil moist, but they also keep weeds at bay, saving time and money.
Mulch made of nature
A mulch of various materials applied to the soil surface is another approach to prevent moisture loss from the soil.
In agronomic crops cultivated in dryland environments, this has become a critical factor. In the winter, a fire can penetrate into a corn field and eat crop leftovers, which I have observed many times. The unburned portion and the section where the fire burned show a significant difference in crop health and yield.
Between the soil and the crop debris, the mulch holds moisture in a layer. Furthermore, the sun heats up the charred region with exposed soil, causing evaporation from the soil surface to speed up.
Mulch also helps to prevent soil compaction caused by heavy rains. Crop residue on the surface may appear messy, but it reduces water loss and serves as a long-term food supply for earthworms and other species.